Wearable Electrocardiography And Physiology Monitoring Ensemble

ABSTRACT

A wearable electrocardiography monitoring ensemble is provided. A first receptacle is defined in a wearable garment by two horizontal bands placed across the wearable garment. A second receptacle is defined by two further horizontal bands positioned across the wearable garment under the first receptacle. A first electrode assembly is positioned within the first receptacle and includes a backing with an electrical connection having an electrode on one end of the electrical connection and terminated at the other end of the electrical connection to connect with a monitor recorder. A second electrode assembly is positioned within the second receptacle and includes a backing with an electrical connection having an electrode on one end of the electrical connection and terminated at the other end of the electrical connection to connect with a further monitor recorder, wherein the first and second electrodes are aligned longitudinally in the wearable garment.

CROSS-REFERENCE TO RELATED APPLICATION

This non-provisional patent application is a continuation of U.S. patentapplication Ser. No. 15/602,003, filed May 22, 2017, pending, which is acontinuation of U.S. Pat. No. 9,655,537, issued May 23, 2017, which is acontinuation-in-part of U.S. Pat. No. 9,717,432, issued Aug. 1, 2017,which is a continuation-in-part of U.S. Pat. No. 9,545,204, issued Jan.17, 2017, and further claims priority under 35 U.S.C. § 119(e) to U.S.Provisional Patent application, Ser. No. 61/882,403, filed Sep. 25,2013, the disclosures of which are incorporated by reference.

FIELD

This application relates in general to electrocardiography andphysiology monitoring and, in particular, to a wearableelectrocardiography and physiology monitoring ensemble.

BACKGROUND

An electrocardiogram (ECG) measures and records electrical potentialsignals and visually depicts heart electrical activity over time.Conventionally, a standard 12-lead configuration is used in-clinic torecord cardiac electrical signals from established chest locations.Physicians use ECGs to diagnose heart problems and other health concernsduring appointments; however, spot ECG recording may not always detectsporadic conditions, including conditions affected by fluctuations inblood pressure, blood sugar, respiratory function, temperature, cardiacphysiology and pathophysiology, or cardiac rhythm.

Physicians may provide improved diagnoses through ambulatory ECGmonitoring that increases the odds of capturing sporadic conditions,during which a subject can also engage in activities of daily living.While long-term extended ambulatory monitoring in-clinic is implausibleand impracticable, diagnostic efficacy can be improved through long-termextended ambulatory ECG monitoring. A 30-day observation period isconsidered the “gold standard,” but has heretofore proven unworkablebecause existing ECG monitoring systems have been arduous to employ,cumbersome to the patient, and expensive.

Extended ECG monitoring is further complicated by patient intolerance tolong-term electrode wear and predisposition to skin irritation.Moreover, natural materials from the patient's body, such as hair,sweat, skin oils, and dead skin cells, can get between an electrode,adhesives, and the skin's surface, which can adversely affect electrodecontact and cardiac signal recording quality. Patient physical movementand clothing can impart forces on the ECG electrode contact point;inflexibly fastened ECG electrodes are particularly prone to becomingdislodged. Precisely re-placing a dislodged ECG electrode may beessential to ensuring signal capture at the same fidelity. Dislodgmentmay occur unbeknownst to the patient, rendering the ECG recordingsworthless.

The high cost of the patient-wearable components used to providelong-term extended ECG monitoring can also negatively influence theavailability and use of monitors. Disposable components, such asadhesive electrodes, ideally should be inexpensive, while more complexcomponents, particularly the electronic hardware that detects andrecords ECG and related physiological data, may be unavoidablyexpensive. Costs can be balanced by designing the electric hardware tobe re-usable, but when the total cost of a full ECG monitoring ensembleremains high, despite the utilization of re-usable parts, the number ofmonitors available for use by healthcare providers can be inhibited.Cost, then, becomes a barrier to entry, which, in turn, can hinder orprevent healthcare providers from obtaining the means with which toefficaciously identify the physiology underlying sporadic cardiacarrhythmic conditions and can ultimately contribute to a failure to makeproper and timely medical diagnose.

ECG data are crucial for diagnosing many cardiovascular conditions. Forexample, detecting abnormal respiratory function with ECG data showingnormal respiratory variation may facilitate diagnosis, prognosis, andtreatment of certain disorders. Moreover, ECG data obtained throughambulatory monitoring, when combined with additional physiological data,can be especially helpful when diagnosing athletes, who present uniqueconcerns not generally observed in a non-physically active patientpopulation. For example, blood sugar plays a strong role in athleticperformance and recovery and correlates with cardiac function.Monitoring respiratory and ECG together can help in diagnosingcardiorespiratory conditions common to athletes, especially since suchconditions not only impair performance, but when combined withovertraining, a cardiorespiratory impairment may lead to severe or eventerminal conditions, including severe bronchoconstriction or suddendeath.

Existing portable devices that monitor cardiac data and otherphysiological data, at best, provide suboptimal results. Such devicescan be inconvenient and may restrain movement; for example, a Holterdevice, which is a wearable ECG monitor with leads placed in a similarposition as used with a standard ECG set-up, is cumbersome, expensive,typically only available by medical prescription, and requires skilledmedical staff to properly position the electrodes.

Wrist monitors, such as the Fitbit product line of activity trackers,manufactured by Fitbit Inc., San Francisco, Calif., and relatedtechnologies, like wristwatch smartphones (also known as smartwatches),such as the Apple Watch, manufactured by Apple Inc., Cupertino, Calif.or the Gear S smartwatch, manufactured by Samsung Electronics Co., Ltd.,Suwon, South Korea, as well as clothing embedded with sensors, such asthe Hexoskin product line of wearable clothing, manufactured by CarréTechnologies, Inc., Montreal, Quebec, Canada, all experience fidelityproblems related to variation in electrode and sensor contact. Gaps insignal quality or interruptions or distortions of the data stream canlead to false positives and false negatives critical to understandingthe relationship between physiological markers and medical events orneeds.

U.S. Pat. No. 8,668,653, to Nagata, et al., discloses an ECG-monitoringshirt with a plurality of electrodes, including four limb electrodes andsensors disposed on a beltline. To fit each of the electrodes on thebody surface of the examinee, a low-irritant acrylic adhesive, forexample, may be applied on each of the electrodes that fit on the body'ssurface. The use of adhered electrodes is incompatible in patients witha predisposition to skin irritation.

Therefore, a need remains for an ambulatory, extended-wear monitor thatcan be used by patients who are intolerant to adhesively-adheredelectrodes; highly mobile individuals, such as athletes, whose movementwill cause adhesively-adhered electrodes to become dislodged; andindividuals of all types in whom the recording high-quality PQRSTU ECGdata and related physiological data are desired.

SUMMARY

Long-term extended ECG monitoring can be provided through a form of ECGor physiological sensor embedded into clothing, rather than on the-skinelectrodes. The garment is made of a material holding the sensor inplace during extended wear through, for example, a compressible,breathable fabric. Electrodes are preferably placed on the garment tocontact the skin along a wearer's sternal midline at specific positionsto enhance P-wave detection and ECG. The electrodes are connected to anECG monitor recorder that is either discrete from or affixed to thegarment and obtains physiological telemetry through a wireless orelectrical interface. Various types of physiological sensors can beprovided.

One embodiment provides a wearable electrocardiography monitoringensemble. A first receptacle is defined in a wearable garment by twohorizontal bands placed across the wearable garment. A second receptacleis defined by two further horizontal bands positioned across thewearable garment and under the first receptacle. A first electrodeassembly is positioned within the first receptacle and includes abacking with an electrical connection having an electrode on one end ofthe electrical connection and terminated at the other end of theelectrical connection to connect with a monitor recorder. A secondelectrode assembly is positioned within the second receptacle andincludes a backing with an electrical connection having an electrode onone end of the electrical connection and terminated at the other end ofthe electrical connection to connect with a further monitor recorder.The first and second electrodes are aligned longitudinally in thewearable garment.

The wearable monitoring ensemble creates a more natural experience forwearers and can be used to produce an expanded dataset for diagnosisbecause the ensemble can collect data during activities of daily livingand can capture cardiovascular events outside of clinical observation,which is otherwise not practicable, especially for athletes.

Still other embodiments will become readily apparent to those skilled inthe art from the following detailed description, wherein are describedembodiments by way of illustrating the best mode contemplated. As willbe realized, other and different embodiments are possible, and theembodiments' several details are capable of modifications in variousobvious respects, all without departing from their spirit and the scope.Accordingly, the drawings and detailed description are to be regarded asillustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are diagrams showing, by way of examples, an extended wearelectrocardiography monitor, including an extended wear electrode patchin accordance with one embodiment, respectively fitted to the sternalregion of a female and a male.

FIG. 3 is a perspective view showing an extended wear electrode patch inaccordance with one embodiment with a monitor recorder inserted.

FIG. 4 is a perspective view showing the extended wear electrode patchof FIG. 3 without a monitor recorder inserted.

FIG. 5 is a top view showing the flexible circuit of the extended wearelectrode patch of FIG. 3.

FIG. 6 is a perspective view showing the extended wear electrode patchin accordance with a further embodiment.

FIG. 7 is an exploded view showing the component layers of the electrodepatch of FIG. 3.

FIG. 8 is a bottom plan view of the extended wear electrode patch ofFIG. 3 with liner partially peeled back.

FIG. 9 is a perspective view of an extended wear electrode patch with aflexile wire electrode assembly in accordance with a still furtherembodiment.

FIG. 10 is perspective view of the flexile wire electrode assembly fromFIG. 9, with a layer of insulating material shielding a bare distal wirearound the midsection of the flexible backing.

FIG. 11 is a bottom view of the flexile wire electrode assembly as shownin FIG. 9.

FIG. 12 is a bottom view of a flexile wire electrode assembly inaccordance with a still yet further embodiment.

FIG. 13 is a perspective view showing the longitudinal midsection of theflexible backing of the electrode assembly from FIG. 9.

FIG. 14 is a longitudinal cross-sectional view of the midsection of theflexible backing of the electrode assembly of FIG. 11.

FIGS. 15A-C are the electrode assembly from FIG. 14 under compressional,tensile, and bending force, respectively.

FIG. 16 is a flow diagram showing a method for constructing astress-pliant physiological electrode assembly in accordance with afurther embodiment.

FIG. 17 is a front view of a wearable electrocardiography and physiologymonitoring ensemble in accordance with a further embodiment.

FIG. 18 is a contact-surface view of a flexible circuit electrodeassembly of the wearable monitoring ensemble of FIG. 17.

FIG. 19 is a contact-surface view of a flexile wire interconnect of thewearable monitoring ensemble of FIG. 17.

FIG. 20 is a contact-surface view of a flexile wire electrode andinterconnect of the wearable monitoring ensemble of FIG. 17.

DETAILED DESCRIPTION

Physiology monitoring can be provided through a wearable monitor thatincludes two components, a flexible extended wear electrode patch and aremovable reusable monitor recorder. FIGS. 1 and 2 are diagrams showing,by way of examples, an extended wear electrocardiography monitor 12,including an extended wear electrode patch 15 in accordance with oneembodiment, respectively fitted to the sternal region of a female 10 anda male 11. In a further embodiment, extended wear monitoring can beprovided in the form of a wearable garment, as further described belowbeginning with reference to FIG. 17 et seq. The wearable monitor 12 sitscentrally (in the midline) on a human chest along the sternum 13oriented top-to-bottom with the monitor recorder 14 preferably situatedtowards a human head. The electrode patch 15 is shaped to fitcomfortably and conform to the contours of a human chest approximatelycentered on the sternal midline 16 (or immediately to either side of thesternum 13). The distal end of the electrode patch 15 extends towardsthe Xiphoid process and lower sternum and, depending upon a human build,may straddle the region over the Xiphoid process and lower sternum. Theproximal end of the electrode patch 15, located under the monitorrecorder 14, is below the manubrium and, depending upon a person'sbuild, may straddle the region over the manubrium.

The placement of the wearable monitor 12 in a location at the sternalmidline 16 (or immediately to either side of the sternum 13)significantly improves the ability of the wearable monitor 12 tocutaneously sense cardiac electric signals, particularly the P-wave (oratrial activity) and, to a lesser extent, the QRS interval signals inthe ECG waveforms that indicate ventricular activity. The sternum 13overlies the right atrium of the heart and the placement of the wearablemonitor 12 in the region of the sternal midline 13 puts the ECGelectrodes of the electrode patch 15 in a location better adapted tosensing and recording P-wave signals than other placement locations,say, the upper left pectoral region. In addition, placing the lower orinferior pole (ECG electrode) of the electrode patch 15 over (or near)the Xiphoid process and lower sternum facilitates sensing of rightventricular activity and provides superior recordation of the QRSinterval.

During use, the electrode patch 15 is first adhered to the skin alongthe sternal midline 16 (or immediately to either side of the sternum13). A monitor recorder 14 is then snapped into place on the electrodepatch 15 to initiate ECG monitoring. FIG. 3 is a perspective viewshowing an extended wear electrode patch 15 in accordance with oneembodiment with a monitor recorder 14 inserted. The body of theelectrode patch 15 is preferably constructed using a flexible backing 20formed as an elongated strip 21 of wrap knit or similar stretchablematerial about 145 mm long and 32 mm at the widest point with a narrowlongitudinal mid-section 23 evenly tapering inward from both sides. Apair of cut-outs 22 between the distal and proximal ends of theelectrode patch 15 create a narrow longitudinal midsection 23 or“isthmus” and defines an elongated “hourglass”-like shape, when viewedfrom above, such as described in commonly-assigned U.S. Pat. No.D744,659, issued Dec. 1, 2015, the disclosure of which is incorporatedby reference. The upper part of the “hourglass” is sized to allow anelectrically non-conductive receptacle 25, sits on top of theoutward-facing surface of the electrode patch 15, to be affixed to theelectrode patch 15 with an ECG electrode placed underneath on thewearer-facing underside, or contact, surface of the electrode patch 15;the upper part of the “hourglass” has a longer and wider profile thanthe lower part of the “hourglass,” which is sized primarily to allowjust the placement of an ECG electrode.

The electrode patch 15 incorporates features that significantly improvewearability, performance, and comfort throughout an extended monitoringperiod. The entire electrode patch 15 is lightweight in construction,which reduces shear forces and allows the patch to be resilient todisadhesing, displacement, or falling off and, critically, to avoidcreating distracting discomfort, even when a person is asleep. Incontrast, the weight of a heavy ECG monitor impedes wearer mobility andwill cause the monitor to constantly tug downwards and press on thewearer's body; frequent adjustments by the wearer are needed to maintaincomfort.

During every day wear, the electrode patch 15 is subjected to pushing,pulling, and torsional movements, including compressional and torsionalforces when the wearer bends forward, and tensile and torsional forceswhen the wearer leans backwards. To counter these stress forces, theelectrode patch 15 incorporates crimp and strain reliefs, as furtherdescribed infra respectively with reference to FIGS. 4 and 5. Inaddition, the cut-outs 22 and longitudinal midsection 23 help minimizeinterference with and discomfort to breast tissue, particularly in women(and gynecomastic men). The cut-outs 22 and longitudinal midsection 23allow better conformity of the electrode patch 15 to sternal bowing andto the narrow isthmus of flat skin that can occur along the bottom ofthe intermammary cleft between the breasts, especially in buxom women.The cut-outs 22 and longitudinal midsection 23 help the electrode patch15 fit nicely between a pair of female breasts in the intermammarycleft. In one embodiment, the cut-outs 22 can be graduated to form thelongitudinal midsection 23 as a narrow in-between stem or isthmusportion about 7 mm wide. In a still further embodiment, tabs 24 canrespectively extend an additional 8 mm to 12 mm beyond the distal andproximal ends of the flexible backing 20 to facilitate purchase whenadhering the electrode patch 15 to or removing the electrode patch 15from the sternum 13. These tabs preferably lack adhesive on theunderside, or contact, surface of the electrode patch 15. Still othershapes, cut-outs and conformities to the electrode patch 15 arepossible.

The monitor recorder 14 removably and reusably snaps into anelectrically non-conductive receptacle 25 during use. The monitorrecorder 14 contains electronic circuitry for recording and storing thewearer's electrocardiography as sensed via a pair of ECG electrodesprovided on the electrode patch 15, such as described incommonly-assigned U.S. Pat. No. 9,730,593, the disclosure of which isincorporated by reference. The circuitry includes a microcontroller,flash storage, ECG signal processing, analog-to-digital conversion(where applicable), and an external interface for coupling to theelectrode patch 15 and to a download station for stored data downloadand device programming. The monitor recorder 14 also includes externalwearer-interfaceable controls, such as a push button to facilitate eventmarking and provide feedback. In a further embodiment, the circuitry,with the assistance of the appropriate types of deployed electrodes orsensors, is capable of monitoring other types of physiology, in additionto ECGs. Still other types of monitor recorder components andfunctionality are possible.

The non-conductive receptacle 25 is provided on the top surface of theflexible backing 20 with a retention catch 26 and tension clip 27 moldedinto the non-conductive receptacle 25 to conformably receive andsecurely hold the monitor recorder 14 in place. The edges of the bottomsurface of the non-conductive receptacle 25 are preferably rounded, andthe monitor recorder 14 is nestled inside the interior of thenon-conductive receptacle 25 to present a rounded (gentle) surface,rather than a sharp edge at the skin-to-device interface.

The electrode patch 15 is intended to be disposable. The monitorrecorder 14, however, is reusable and can be transferred to successiveelectrode patches 15 to ensure continuity of monitoring. The placementof the wearable monitor 12 in a location at the sternal midline 16 (orimmediately to either side of the sternum 13) benefits long-termextended wear by removing the requirement that ECG electrodes becontinually placed in the same spots on the skin throughout themonitoring period. Instead, the wearer is free to place an electrodepatch 15 anywhere within the general region of the sternum 13.

As a result, at any point during ECG monitoring, the wearer's skin isable to recover from the wearing of an electrode patch 15, whichincreases wearer comfort and satisfaction, while the monitor recorder 14ensures ECG monitoring continuity with minimal effort. A monitorrecorder 14 is merely unsnapped from a worn out electrode patch 15, theworn out electrode patch 15 is removed from the skin, a new electrodepatch 15 is adhered to the skin, possibly in a new spot immediatelyadjacent to the earlier location, and the same monitor recorder 14 issnapped into the new electrode patch 15 to reinitiate and continue theECG monitoring.

During use, the electrode patch 15 is first adhered to the skin in thesternal region. FIG. 4 is a perspective view showing the extended wearelectrode patch 15 of FIG. 3 without a monitor recorder 14 inserted. Aflexible circuit 32 is adhered to each end of the flexible backing 20. Adistal circuit trace 33 from the distal end 30 of the flexible backing20 and a proximal circuit trace (not shown) from the proximal end 31 ofthe flexible backing 20 electrically couple ECG electrodes (not shown)with a pair of electrical pads 34. In a further embodiment, the distaland proximal circuit traces are replaced with interlaced or sewn-inflexible wires, as further described infra beginning with reference toFIG. 9. The electrical pads 34 are provided within a moisture-resistantseal 35 formed on the bottom surface of the non-conductive receptacle25. When the monitor recorder 14 is securely received into thenon-conductive receptacle 25, that is, snapped into place, theelectrical pads 34 interface to electrical contacts (not shown)protruding from the bottom surface of the monitor recorder 14. Themoisture-resistant seal 35 enables the monitor recorder 14 to be worn atall times, even during bathing or other activities that could expose themonitor recorder 14 to moisture or adverse conditions.

In addition, a battery compartment 36 is formed on the bottom surface ofthe non-conductive receptacle 25. A pair of battery leads (not shown)from the battery compartment 36 to another pair of the electrical pads34 electrically interface the battery to the monitor recorder 14. Thebattery contained within the battery compartment 35 can be replaceable,rechargeable or disposable.

The monitor recorder 14 draws power externally from the battery providedin the non-conductive receptacle 25, thereby uniquely obviating the needfor the monitor recorder 14 to carry a dedicated power source. Thebattery contained within the battery compartment 36 can be replaceable,rechargeable or disposable. In a further embodiment, the ECG sensingcircuitry of the monitor recorder 14 can be supplemented with additionalsensors, including an SpO2 sensor, a blood pressure sensor, atemperature sensor, respiratory rate sensor, a glucose sensor, an airflow sensor, and a volumetric pressure sensor, which can be incorporateddirectly into the monitor recorder 14 or onto the non-conductivereceptacle 25.

The placement of the flexible backing 20 on the sternal midline 16 (orimmediately to either side of the sternum 13) also helps to minimize theside-to-side movement of the wearable monitor 12 in the left- andright-handed directions during wear. However, the wearable monitor 12 isstill susceptible to pushing, pulling, and torquing movements, includingcompressional and torsional forces when the wearer bends forward, andtensile and torsional forces when the wearer leans backwards. To counterthe dislodgment of the flexible backing 20 due to compressional andtorsional forces, a layer of non-irritating adhesive, such ashydrocolloid, is provided at least partially on the underside, orcontact, surface of the flexible backing 20, but only on the distal end30 and the proximal end 31. As a result, the underside, or contactsurface of the longitudinal midsection 23 does not have an adhesivelayer and remains free to move relative to the skin. Thus, thelongitudinal midsection 23 forms a crimp relief that respectivelyfacilitates compression and twisting of the flexible backing 20 inresponse to compressional and torsional forces. Other forms of flexiblebacking crimp reliefs are possible.

Unlike the flexible backing 20, the flexible circuit 32 is only able tobend and cannot stretch in a planar direction. FIG. 5 is a top viewshowing the flexible circuit 32 of the extended wear electrode patch 15of FIG. 3. A distal ECG electrode 38 and proximal ECG electrode 39 arerespectively coupled to the distal and proximal ends of the flexiblecircuit 32 to serve as electrode signal pickups. The flexible circuit 32preferably does not extend to the outside edges of the flexible backing20, thereby avoiding gouging or discomforting the wearer's skin duringextended wear, such as when sleeping on the side. During wear, the ECGelectrodes 38, 39 must remain in continual contact with the skin. Astrain relief 40 is defined in the flexible circuit 32 at a locationthat is partially underneath the battery compartment 36 when theflexible circuit 32 is affixed to the flexible backing 20. The strainrelief 40 is laterally extendable to counter dislodgment of the ECGelectrodes 38, 39 due to tensile and torsional forces. A pair of strainrelief cutouts 41 partially extend transversely from each opposite sideof the flexible circuit 32 and continue longitudinally towards eachother to define in ‘S’-shaped pattern, when viewed from above. Thestrain relief respectively facilitates longitudinal extension andtwisting of the flexible circuit 32 in response to tensile and torsionalforces. Other forms of circuit board strain relief are possible.

The flexible circuit 32 can be provided either above or below theflexible backing 20. FIG. 6 is a perspective view showing the extendedwear electrode patch 15 in accordance with a further embodiment. Theflexible circuit (not shown) is provided on the underside, or contact,surface of the flexible backing 20 and is electrically interfaced to theset of electrical pads 34 on the bottom surface of the non-conductivereceptacle 25 through electrical contacts (not shown) pierced throughthe flexible backing 20.

The electrode patch 15 is intended to be a disposable component, whichenables a wearer to replace the electrode patch 15 as needed throughoutthe monitoring period, while maintaining continuity of physiologicalsensing through reuse of the same monitor recorder 14. FIG. 7 is anexploded view showing the component layers of the electrode patch 15 ofFIG. 3. The flexible backing 20 is constructed of a wearable gauze,latex, woven textile, or similar wrap knit or stretchable and wear-safematerial 44, such as a Tricot-type linen with a pressure sensitiveadhesive (PSA) on the underside, or contact, surface. The ends of thewearable material 44 are coated with a layer 43 of non-irritatingadhesive, such as hydrocolloid, to facilitate long-term wear, while theunadhesed narrowed midsection rides freely over the skin. Thehydrocolloid, for instance, is typically made of mineral oil, celluloseand water and lacks any chemical solvents, so should cause littleitching or irritation. Moreover, hydrocolloid can be manufactured intoan appropriate thickness and plasticity and provides cushioning betweenthe relatively rigid and unyielding non-conductive receptacle 25 and thewearer's skin. In a further embodiment, the layer of non-irritatingadhesive can be contoured, such as by forming the adhesive with aconcave or convex cross-section; surfaced, such as through stripes orcrosshatches of adhesive, or by forming dimples in the adhesive'ssurface; or applied discontinuously, such as with a formation ofdiscrete dots of adhesive.

As described supra with reference to FIG. 5, a flexible circuit can beadhered to either the outward facing surface or the underside, orcontact, surface of the flexible backing 20. For convenience, a flexiblecircuit 47 is shown relative to the outward facing surface of thewearable material 44 and is adhered respectively on a distal end by adistal electrode seal 45 and on a proximal end by a proximal electrodeseal 45. In a further embodiment, the flexible circuit 47 can beprovided on the underside, or contact, surface of the wearable material44. Through the electrode seals, only the distal and proximal ends ofthe flexible circuit 47 are attached to the wearable material 44, whichenables the strain relief 40 (shown in FIG. 5) to respectivelylongitudinally extend and twist in response to tensile and torsionalforces during wear. Similarly, the layer 43 of non-irritating adhesiveis provided on the underside, or contact, surface of the wearablematerial 44 only on the proximal and distal ends, which enables thelongitudinal midsection 23 (shown in FIG. 3) to respectively bow outwardand away from the sternum 13 or twist in response to compressional andtorsional forces during wear.

A pair of openings 46 is defined on the distal and proximal ends of thewearable material 44 and layer 43 of non-irritating adhesive for ECGelectrodes 38, 39 (shown in FIG. 5). The openings 46 serve as “gel”wells with a layer of hydrogel 41 being used to fill the bottom of eachopening 46 as a conductive material that aids electrode signal capture.The entire underside, or contact, surface of the flexible backing 20 isprotected prior to use by a liner layer 40 that is peeled away, as shownin FIG. 8.

The non-conductive receptacle 25 includes a main body 54 that is moldedout of polycarbonate, ABS, or an alloy of those two materials to providea high surface energy to facilitate adhesion of an adhesive seal 53. Themain body 54 is attached to a battery printed circuit board 52 by theadhesive seal 53 and, in turn, the battery printed circuit board 52 isadhered to the flexible circuit 47 with an upper flexible circuit seal50. A pair of conductive transfer adhesive points 51 or, alternatively,soldered connections, or electromechanical connections, includingmetallic rivets or similar conductive and structurally unifyingcomponents, connect the circuit traces 33, 37 (shown in FIG. 5) of theflexible circuit 47 to the battery printed circuit board 52. The mainbody 54 has a retention catch 26 and tension clip 27 (shown in FIG. 3)that fixably and securely receive a monitor recorder 14 (not shown), andincludes a recess within which to circumferentially receive a die cutgasket 55, either rubber, urethane foam, or similar suitable material,to provide a moisture resistant seal to the set of pads 34. Other typesof design, arrangement, and permutation are possible.

In a still further embodiment, the flexible circuit 32 (shown in FIG. 4)and distal ECG electrode 38 and proximal ECG electrode 39 (shown in FIG.5) are replaced with a pair of interlaced flexile wires. The interlacingof flexile wires through the flexible backing 20 reduces bothmanufacturing costs and environmental impact, as further describedinfra. The flexible circuit and ECG electrodes are replaced with a pairof flexile wires that serve as both electrode circuit traces andelectrode signal pickups. FIG. 9 is a perspective view of an extendedwear electrode patch 15 with a flexile wire electrode assembly inaccordance with a still further embodiment. The flexible backing 20maintains the unique narrow “hourglass”-like shape that aids long termextended wear, particularly in women, as described supra with referenceto FIG. 3. For clarity, the non-conductive receptacle 25 is omitted toshow the exposed battery printed circuit board 62 that is adheredunderneath the non-conductive receptacle 25 to the proximal end 31 ofthe flexible backing 20. Instead of employing flexible circuits, a pairof flexile wires are separately interlaced or sewn into the flexiblebacking 20 to serve as circuit connections for an anode electrode leadand for a cathode electrode lead.

To form a distal electrode assembly, a distal wire 61 is interlaced intothe distal end 30 of the flexible backing 20, continues along an axialpath through the narrow longitudinal midsection of the elongated strip,and electrically connects to the battery printed circuit board 62 on theproximal end 31 of the flexible backing 20. The distal wire 61 isconnected to the battery printed circuit board 62 by stripping thedistal wire 61 of insulation, if applicable, and interlacing or sewingthe uninsulated end of the distal wire 61 directly into an exposedcircuit trace 63. The distal wire-to-battery printed circuit boardconnection can be made, for instance, by back stitching the distal wire61 back and forth across the edge of the battery printed circuit board62. Similarly, to form a proximal electrode assembly, a proximal wire(not shown) is interlaced into the proximal end 31 of the flexiblebacking 20. The proximal wire is connected to the battery printedcircuit board 62 by stripping the proximal wire of insulation, ifapplicable, and interlacing or sewing the uninsulated end of theproximal wire directly into an exposed circuit trace 64. The resultingflexile wire connections both establish electrical connections and helpto affix the battery printed circuit board 62 to the flexible backing20.

The battery printed circuit board 62 is provided with a batterycompartment 36. A set of electrical pads 34 are formed on the batteryprinted circuit board 62. The electrical pads 34 electrically interfacethe battery printed circuit board 62 with a monitor recorder 14 whenfitted into the non-conductive receptacle 25. The battery compartment 36contains a spring 65 and a clasp 66, or similar assembly, to hold abattery (not shown) in place and electrically interfaces the battery tothe electrical pads 34 through a pair battery leads 67 for powering theelectrocardiography monitor 14. Other types of battery compartment arepossible. The battery contained within the battery compartment 36 can bereplaceable, rechargeable, or disposable.

In a yet further embodiment, the circuit board and non-conductivereceptacle 25 are replaced by a combined housing that includes a batterycompartment and a plurality of electrical pads. The housing can beaffixed to the proximal end of the elongated strip through theinterlacing or sewing of the flexile wires or other wires or threads.

The core of the flexile wires may be made from a solid, stranded, orbraided conductive metal or metal compounds. In general, a solid wirewill be less flexible than a stranded wire with the same totalcross-sectional area, but will provide more mechanical rigidity than thestranded wire. The conductive core may be copper, aluminum, silver, orother material. The pair of the flexile wires may be provided asinsulated wire. In one embodiment, the flexile wires are made from amagnet wire from Belden Cable, catalogue number 8051, with a solid coreof AWG 22 with bare copper as conductor material and insulated bypolyurethane or nylon. Still other types of flexile wires are possible.In a further embodiment, conductive ink or graphene can be used to printelectrical connections, either in combination with or in place of theflexile wires.

In a still further embodiment, the flexile wires are uninsulated. FIG.10 is perspective view of the flexile wire electrode assembly from FIG.9, with a layer of insulating material 69 shielding a bare uninsulateddistal wire 61 around the midsection on the contact side of the flexiblebacking. On the contact side of the proximal and distal ends of theflexible backing, only the portions of the flexile wires serving aselectrode signal pickups are electrically exposed and the rest of theflexile wire on the contact side outside of the proximal and distal endsare shielded from electrical contact. The bare uninsulated distal wire61 may be insulated using a layer of plastic, rubber-like polymers, orvarnish, or by an additional layer of gauze or adhesive (ornon-adhesive) gel. The bare uninsulated wire 61 on the non-contact sideof the flexible backing may be insulated or can simply be leftuninsulated.

Both end portions of the pair of flexile wires are typically placeduninsulated on the contact surface of the flexible backing 20 to form apair of electrode signal pickups. FIG. 11 is a bottom view of theflexile wire electrode assembly as shown in FIG. 9. When adhered to theskin during use, the uninsulated end portions of the distal wire 61 andthe proximal wire 71 enable the monitor recorder 14 to measure dermalelectrical potential differentials. At the proximal and distal ends ofthe flexible backing 20, the uninsulated end portions of the flexilewires may be configured into an appropriate pattern to provide anelectrode signal pickup, which would typically be a spiral shape formedby guiding the flexile wire along an inwardly spiraling pattern. Thesurface area of the electrode pickups can also be variable, such as byselectively removing some or all of the insulation on the contactsurface. For example, an electrode signal pickup arranged by sewinginsulated flexile wire in a spiral pattern could have a crescent-shapedcutout of uninsulated flexile wire facing towards the signal source.

In a still yet further embodiment, the flexile wires are left freelyriding on the contact surfaces on the distal and proximal ends of theflexible backing, rather than being interlaced into the ends of theflexible backing 20. FIG. 12 is a bottom view of a flexile wireelectrode assembly in accordance with a still yet further embodiment.The distal wire 61 is interlaced onto the midsection and extends anexposed end portion 72 onto the distal end 30. The proximal wire 71extends an exposed end portion 73 onto the proximal end 31. The exposedend portions 72 and 73, not shielded with insulation, are furtherembedded within an electrically conductive adhesive 81. The adhesive 81makes contact to skin during use and conducts skin electrical potentialsto the monitor recorder 14 (not shown) via the flexile wires. Theadhesive 81 can be formed from electrically conductive, non-irritatingadhesive, such as hydrocolloid.

The distal wire 61 is interlaced or sewn through the longitudinalmidsection of the flexible backing 20 and takes the place of theflexible circuit 32. FIG. 13 is a perspective view showing thelongitudinal midsection of the flexible backing of the electrodeassembly from FIG. 9. Various stitching patterns may be adopted toprovide a proper combination of rigidity and flexibility. In simplestform, the distal wire 61 can be manually threaded through a plurality ofholes provided at regularly-spaced intervals along an axial path definedbetween the battery printed circuit board 62 (not shown) and the distalend 30 of the flexible backing 20. The distal wire 61 can be threadedthrough the plurality of holes by stitching the flexile wire as a single“thread.” Other types of stitching patterns or stitching of multiple“threads” could also be used, as well as using a sewing machine orsimilar device to machine-stitch the distal wire 61 into place, asfurther described infra. Further, the path of the distal wire 61 neednot be limited to a straight line from the distal to the proximal end ofthe flexible backing 20.

The distal wire 61 is flexile yet still retains a degree of rigiditythat is influenced by wire gauge, composition, stranding, insulation,and stitching pattern. For example, rigidity decreases with wire gauge;and a solid core wire tends to be more rigid than a stranded core of thesame gauge. The combination of the flexibility and the rigidity of theportion of the distal wire 61 located on or close to the midsectioncontributes to the overall strength and wearability of the patch. FIG.14 is a longitudinal cross-sectional view of the midsection of theflexible backing 20 of the electrode assembly of FIG. 11. FIGS. 15A-Care the electrode assembly from FIG. 14 under compressional, tensile,and bending force, respectively. The relative sizes of the distal wire61 and flexible backing 20 are not to scale and are exaggerated forpurposes of illustration.

The interlacing of the distal wire 61 through the narrow longitudinalmidsection 22 of the flexible backing 20 bends the distal wire 61 into aline of rounded stitches that alternate top and bottom, which can beadvantageous to long term wearability. First, the tension of the roundedstitches reinforces the planar structure of the narrow longitudinalmidsection 22 and spreads a dislodging force impacting on one end of theflexible backing 20 to the other end of the flexible backing 20. Second,the rounded stitches leave room for stretching, compressing, bending,and twisting, thus increasing the wearability of the patch extended wearelectrode patch 15 by facilitating extension, compression, bending, andtwisting of the narrow longitudinal midsection 22 in response totensile, compressional, bending, and torsional forces.

In a further embodiment, the distal wire and the proximal wire may bestitched or sewn into the flexible backing 20. Depending upon the typeof stitching used, the distal or proximal wire may use more than oneindividual wire. For instance, a conventional sewing machine used tostitch fabrics uses a spool of thread and a bobbin, which are both woundwith thread that together allow the creation of various stitchingpatterns, such as the lockstitch. Other type of stitching patterns arepossible. Additionally, where more than one “threads” are used forstitching, the flexile wire may constitute all of the “threads,” therebyincreasing redundancy of the circuit trace thus formed. Alternatively,just one (or fewer than all) of the threads may be conductive, with thenon-conductive threads serving to reinforce the strength of the flexilewire connections and flexible backing 20. The additional threads can bemade from line, threads, or fabrics of sufficient mechanical strengthand do not need to be conductive; alternatively, the same flexile wirescan be employed to serve as the additional threads.

Conventionally, flexible circuits, such as the flexible circuit 32(shown in FIG. 4) that connects the distal ECG electrode 38 and proximalECG electrode 39 (shown in FIG. 5) to the battery printed circuit board62 (shown in FIG. 9), are constructed using subtractive processes. Ingeneral, a flexible circuit interconnects electronic components withcustom point-to-point circuit traces and is typically constructed byforming the conductive circuit traces on a thin film of insulatingpolymer. A flexible circuit is not an off-the-shelf component; rather,each flexible circuit is designed with a specific purpose in mind.Changes to a flexible circuit's design will generally requirefabricating entirely new flexible circuits, as the physical circuittraces on the polymer film cannot be changed.

Manufacturing a flexible circuit typically requires the use ofsophisticated and specialized tools, coupled with environmentallyunfriendly processes, including depositing copper on a polyamide core,etching away unwanted copper with inline etching or an acid bath toretain only the desired conductive circuit traces, and applying acoverlay to the resulting flexible circuit. Significant amounts ofhazardous waste are generated by these subtractive processes during thefabrication of each flexible circuit. Properly disposing of suchhazardous waste is expensive and adds to the costs of the flexiblecircuit.

In the still further embodiment described supra beginning with referenceto FIG. 9, the distal and proximal flexile wires replace the flexiblecircuit 32 and enables the electrode assembly to be constructed usingadditive processes with off-the-shelf, low cost components. The flexilewires serve the triple functions of an electrode signal pickup,electrical circuit trace, and support for structural integrity andmalleability of the electrode assembly.

The general manner of constructing the electrode assembly can be appliedto other forms of electronic components in which custom point-to-pointcircuit traces need to be affixed to a gauze or textile backing, as wellas backings made from other materials. The circuit traces are replacedby the interlaced or sewn flexile wires, and the ends of each flexilewire are terminated, as appropriate to the application. The flexilewires may, by example, connect two circuit boards, or connect to anelectrical terminal, power source, or electrical component. In addition,flexile wires may be used to replace a printed circuit board entirely,with each flexile wire serving as a form of sewn interconnect betweentwo or more discrete components, including resistors, capacitors,transistors, diodes, operational amplifiers (op amps) and otherintegrated circuits, and other electronic or electromechanicalcomponents.

By way of illustration, the flexile wires will be described asterminated for use in an electrode assembly, specifically, as terminatedon one end to form an electrode signal pickup and on the other end toconnect into a circuit board. Constructing the electrode assemblyentails interlacing, including manually threading, or machine sewing theflexile, conductive wire through the flexible backing 20. FIG. 16 is aflow diagram showing a method 90 for constructing a stress-pliantphysiological electrode assembly in accordance with a furtherembodiment. The method can be performed by a set of industrial machines,including a gauze cutting machine to cut the flexible backing 20 toform; a hole punch to cut a plurality of holes provided atregularly-spaced intervals; a stitching or sewing machine to interleaveor sew the flexile wire through the flexible backing 20; a wire stripperor plasma jet to remove insulation from the flexile wire, whenapplicable; and a glue or adhesive dispenser to embed or coat electrodesignal pickup in hydrocolloid gel or equivalent non-irritating adhesive.Other forms or combinations of industrial machines, including a singlepurpose-built industrial machine, could be used.

As an initial step, a backing is cut to shape and, if required, holesare cut at regularly-spaced intervals along an axial path (step 91)through which the flexile wire will be interlaced. Holes will need to becut, for instance, if the flexile wire is to be hand-guided through thebacking, or where the backing is cut from a material that is difficultto puncture with a threaded needle, such as used by a sewing machine. Inone embodiment, the backing is cut from wearable gauze, latex, woventextile, or similar wrap knit or stretchable and wear-safe material,such as a Tricot-type linen; the resulting backing is flexible andyielding. The backing is also cut into an elongated “hourglass”-likeshape, when viewed from above, with a pair of cut-outs and alongitudinal midsection that together help minimize interference withand discomfort to breast tissue, particularly in women (and gynecomastiamen), such as described supra with reference to FIG. 3. The backing canbe cut into other shapes as appropriate to need. In addition, dependingupon the application, other materials could be substituted for thebacking. For example, neoprene, such as used in wetsuits, could be usedwhere a high degree of elasticity and ruggedness is desired.

The flexile wire is then interlaced or sewn into the backing (step 92).Interlacing can be performed by a machine that guides the flexile wirethrough the holes previously cut in the material in a crisscrossed,interwoven, or knitted fashion, as well as by hand. The flexile wire canalso be guided through the backing without first cutting holes, providedthat the weave of the material is sufficiently loose to allow passage ofthe flexile wire if the flexile wire is otherwise incapable of passingthrough the backing without the assistance of a needle or other piercinginstrument.

Alternatively, the flexile wire could be sewn into the backing by usingthe flexile wire as “thread” that is stitched into place using a needleor similar implement. If a single flexile wire is employed, thestitching will be a line of rounded stitches that alternate top andbottom, as described supra; however, if more than one flexile wire isused, or the stitching pattern requires the use of more than one thread,other forms of conventional machine-stitching patterns could beemployed, such as a lockstitch.

Once completed, the interlacing or sewing of the flexile wire into thebacking creates an integrated point-to-point electrical path that takesthe place of a custom circuit trace using an additive, rather thansubtractive, manufacturing process. The flexile wire can be interlacedor sewn along a straight, curved, or arbitrary path. One flexile wire isrequired per point-to-point circuit trace. The strength and pliabilityof the flexile wire reinforces the backing and, in the still furtherembodiment described supra beginning with reference to FIG. 9,facilitates extension, compression, bending, and twisting of the narrowlongitudinal midsection 22 in response to tensile, compressional,bending, and torsional forces. Thus, the path of the flexile wire alongthe backing can be mapped to take advantage of the strength andreinforcing properties of the flexile wire, which, when interlaced orsewn into the backing, help the backing counter the stresses to whichthe backing will be subjected when deployed.

The flexile wire itself may be insulated or bare (step 93). When one endof the flexile wire is connected to (or forms) an electrode,particularly a dermal physiology electrode that senses electricalpotentials on the skin's surface, insulated flexile wire will ordinarilybe used, with only a portion of the flexile wire incident to theelectrode stripped of insulation. However, bare uninsulated flexile wirecould alternatively be used throughout, so long as those portions of theuninsulated flexile wire that are exposed on the contact-facing surfaceof the backing are insulated and shielded from electrical contact (step94), such as by applying a layer of plastic, rubber-like polymers, orvarnish, or by an additional layer of gauze or adhesive (ornon-adhesive) gel over the exposed wire. The uninsulated flexile wireexposed on other surfaces of the backing could also be insulated orsimply be left bare.

One end of the flexile wire may be terminated as an electrode signalpickup (step 95). If insulated flexile wire is used, a portion of theend of the flexile wire is stripped of insulation (step 96) using, forinstance, a wire stripper or plasma jet. The electrode signal pickupcould either be formed by interlacing (or sewing) the flexile wire (step97) into the backing in the shape of the desired electrode (step 98) orpositioned over the contact-facing area of the backing designated toserve as an electrode signal pickup and embedded within an electricallyconductive adhesive (step 99). In a yet further embodiment, the flexilewire could be terminated as a connection to a discrete electrode, suchas by sewing an uninsulated portion of the end of the electrode wireinto the discrete electrode to thereby establish an electrical contactand affix the discrete electrode to the backing. The Universal ECG EKGelectrode, manufactured by Bio Protech Inc., Tustin, Calif., is oneexample of a discrete electrode.

Finally, the other end of the flexile wire may be terminated as aconnection to a circuit board (step 100). The flexile wire can beinterlaced or sewn onto the circuit board, for instance, by backstitching the flexile wire back and forth across the edge of the circuitboard to thereby establish an electrical contact and affix the discreteelectrode to the backing.

In a further embodiment, flexile wire can be used to replace all or partof a printed circuit board, such as battery printed circuit board 62used in constructing a stress-pliant physiological electrode assembly,as described supra, or for any other application that requiresinterconnection of electrical or electro mechanical components on aphysical substrate or backing. Flexile wire in place of conductivecircuit traces can work especially well with simple circuit boardlayouts, where ample space between components and relativelyuncomplicated layouts are amenable to stitched-in interconnections. Inaddition, the use of flexile wire can simplify circuit layout design inmultilayer circuits, as insulated flexile wires can be run across eachother in situations that would otherwise require the use of a multilayerprinted circuit board or similar solution.

Through such use of flexile wire, a printed circuit board can be omittedin whole or in part. Interconnects between and connections to theelectronic and electro mechanical components formerly placed on theprinted circuit board can instead be sewn from flexile wire. Forinstance, the battery printed circuit board 62 can be replaced byflexile wire interconnects that connect the electrodes to a sewn set ofelectrical pads formed by over-stitching the flexile wire intoelectrical contact surfaces of sufficient size to interface with amonitor recorder 14 when fitted into the non-conductive receptacle 25.Likewise, the spring 65 and clasp 66 can be sewn in place using flexilewire to hold a battery in place with flexile wire interconnectsconnecting the battery to a sewn set of electrical pads formed byover-stitching the flexile wire into electrical contact surfaces ofsufficient size to interface with a monitor recorder 14 when fitted intothe non-conductive receptacle 25. Still other approaches to replacingprinted circuit boards with flexile wire interconnects are possible.

The resultant stress-pliant physiological electrode assembly may beelectrically coupled to a broad range of physiological monitors notlimited to electrocardiographic measurement. The foregoing method ofconstructing a stress-pliant electrode assembly is adaptable tomanufacturing other forms of dermal electrodes, including electrodes forelectrocardiography, electroencephalography, and skin conductancemeasurements. Further, by adjusting the number of electrodes, thedistances among the electrode signal pickups, and the thickness of theflexile wire, the method can be adapted to manufacturing at low cost anelectrode assembly that is lightweight and resistant to tensile,compressional and torsional forces, thus contributing to long-term wearand versatility.

The extended wear electrocardiography monitor, described supra withreference to FIGS. 1-16, is generally worn as a patch adhered to theskin during use. Some patients, however, may not be able to wear anadhesive patch due to allergic reaction, skin condition, or otherfactors that make the wearing of an adhesive patch, even for a shortduration, either undesirable or impracticable. Moreover, athletes,particularly when interested in monitoring performance during trainingand sports activities, may find the wearing of an adhesive patch ahindrance to movement and at odds with performance monitoring.

As an alternative to an adhesively-attached electrode patch, theelectrodes of the extended wear electrocardiography monitor can beintegrated into a wearable garment that can be coupled with a monitorrecorder 14 (shown in FIG. 1) or similar recordation device. FIG. 17 isa front view of a wearable electrocardiography and physiology monitoringensemble 300 in accordance with a further embodiment. The wearablemonitoring ensemble 300 is provided through a wearable garment 301, suchas a shirt, blouse, or tunic, that is worn about the upper region of thetorso that is equipped with an electrode assembly 313. The wearablegarment 301 is constructed, at least in part, using a compressible andelastomeric material, such as Spandex, formerly manufactured by E.I. duPont de Nemours and Company (“DuPont”), Wilmington, Del.; Lycra,manufactured by Koch Industries, Inc., Wichita, Kans.; or elastane.Other types or combinations of compressible and elastomeric materialsare possible.

An electrode patch achieves fully continuous electrode contact throughan adhesive or a fixing agent that adheres a gauze or similarly-woven orflexible material against the skin; the gauze serves as a backing toeach electrode, which is held captive and firmly in place between theskin and the gauze. In addition, the electrodes themselves could becoated with an adhesive to self-adhere the electrodes directly to theskin. In both forms, the presence of adhesive on the skin's surface canbe at variance with extended long-term wear, especially on patients withsensitive or fragile skin or who have allergies or sensitivities to thechemicals or materials used in adhesive patches.

The construction of the wearable garment 301 employs an internalstructure 302 that obviates the need to use adhesives or other fixingagents to hold electrophysiology and physiology sensing electrodes intoplace. The internal structure 302 allows the wearable garment 301 toexert a compressive force against an electrode assembly 313 that issufficient to keep the electrodes 309 and 310 in usably-continuouscontact with the wearer's skin throughout the monitoring period. Theelectrode assembly 313 contains at least two electrodes 309 and 310 thatare both affixed to a backing, either individually or combined. Theelectrode assembly 313 is provided on an inside-facing surface of thewearable garment 301 on an underside of the internal structure 302 tokeep the electrode assembly 313 firmly against the wearer's skin. Incontrast to an electrode-equipped adhesive patch, the wearable garment301 permits unconstrained free movement during monitoring and the weareris typically unaware of the presence of the electrode assembly 313.However, to effectively measure electrophysiology, the electrodes 309and 310 need to be kept in fairly continuous, albeit not absolutelyconstant, physical contact with the skin.

The wearable monitoring ensemble 300 obviates the necessity of adhesivesor other fixing agents that adhere directly to the skin by utilizing theinternal structure 302 of the wearable garment 301 to place and retainthe electrode assembly 313 securely against the skin. To some degree,internal structure 302 inherent in the overall design of the wearablegarment 301, when in the form of clothing worn about the torso,specifically, a shirt, blouse, or tunic, will retain the relativepositions of the various panels that make up the wearable garment 301 inplace during wear. Elements of the inherent garment design include, forinstance, the openings for the arms 303 a and 303 b, the neck 304, andtorso 305 proper. Other elements of inherent garment design arepossible.

To facilitate monitoring purposes, though, the relative position of thepanel upon which the sensory assembly 313 is affixed to the internalstructure 302 on the inside surface of the wearable garment 301 must bekept from dramatically shifting about; the location of the electrodeassembly 313 ought to be sufficiently stable, so as to avoid displacingthe underlying electrodes 309 and 310 to the degree that cardiacelectric potential signals are degraded or change character.

The inherent design of the wearable garment 301 only provides a partialsolution and these structures alone will not suffice to maintain theelectrode assembly 313 in fairly continuous physical contact with theskin. The internal structure 302 of the wearable garment 301 is biasedto press snuggly against the skin in at least those portions of thewearable garment 301 where the electrode assembly 313 need be held in arelatively stable orientation. The compressive bias is provided by thecompressible and elastomeric material and the internal structure 302,which can include elastic bands 306 a, 306 b, 306 c, and 306 d, embeddedlongitudinally across the chest, or by a combination of fabriccomponents with varying characteristics of elasticity.

The compressive force imparted by the wearable garment 301 on theelectrode assembly 313 is provided by placing the electrode assembly 313on an inside surface of the wearable garment 301 on an underside of theinternal structure 302, such that the electrode assembly 313 is firmly“pinned” in place against the skin, yet not adhered. The amount ofside-to-side shift or momentary loss of contact that can be toleratedwithout signal degradation or compromise depends upon the monitoringlocation. For instance, to optimize capture of P-wave signals, theelectrode assembly 313 can advantageously be positioned axially alongthe midline of a wearer's sternum, such as described incommonly-assigned U.S. Pat. No. 9,700,227, the disclosure of which isincorporated by reference. To secure the electrode assembly 313 in thedesired orientation axially along the sternal midline, the wearablegarment 301 integrates a bias that imparts compressive forcecircumferentially about the wearer's torso; the compressive force issufficient to keep the two electrodes 309 and 310 against the skin forthe majority of the time during wear and monitoring. However, whereas anelectrode patch seeks to keep the electrodes in continuous andstationary contact with the skin at all times, the electrodes here arepermitted to actively “float” over the skin's surface, so long at leasta part of an electrode's surface contacts the skin. Thus, to a limitedextent, the electrodes 309 and 310 can slide around the general regionon the skin where a cardiac electric potential signal sensing isdesired. In addition, the occasional loss of signal pick up that canoccur if the electrode assembly 313 briefly loses contact with the skin,such as happens if the wearer makes a sudden movement, can be weathered;cardiac electric potential signals lost through a momentary loss of skincontact are not likely to adversely degrade overall signal fidelity, solong as the loss of contact is sufficiently brief and spans say, no morethan a few heartbeats. As a result, the wearable garment 301 needs tokeep the electrode assembly 313 oriented on the skin in the same overallspot, but the electrode assembly 313 need not be fixed as an absolutelystationary location and some degree of sliding movement or “float” alongthe skin's surface is permissible.

The electrode assembly 313 is also provided with two electricalconnections 311 and 312 through which a monitor recorder can receive andrecord electrical potential signals. One end of each of the electricalconnections 311 and 312 is connected to one of the electrodes 309 and310, while the other end of each of the electrical connections 311 and312 is terminated to suit interfacing with a compatible form of monitorrecorder. In one embodiment, the electrical connections 311 and 312 canbe connected to the pair of electrical pads 34 provided on thenon-conductive receptacle 25 (shown in FIG. 4) to electrically couplethe electrodes 309 and 310 to a reusable monitor recorder 14. In afurther embodiment, the electrical connections can be adapted towirelessly interface to a wireless-capable monitor recorder. Each of theelectrical connections 311 and 312 are interfaced to a wirelesstransceiver over which the cardiac electric potential signals sensed bythe electrodes 309 and 310 are transmitted. Other forms of terminatingthe electrical connections 311 and 312 to interface to a monitorrecorder are possible.

The electrode assembly 313 can be packaged in at least three differentforms, including a flexible circuit electrode assembly and flexile wireelectrode assemblies with discrete or sewn-in electrodes. These forms ofsensor assemblies will now be discussed. First, FIG. 18 is acontact-surface view of a flexible circuit electrode assembly 313 of thewearable monitoring ensemble 300 of FIG. 17. The electrode assembly 313contains two electrodes 309 and 310, which are formed on two flexiblecircuits 314 and 315, respectively. In a further embodiment, the twoelectrodes 309 and 310 can be formed on a single flexible circuit. Theflexile circuits include circuit traces 311 and 312 that terminaterespectively with electrical pads 316 and 317 for mating with, forinstance, the pair of electrical pads 34 provided on the non-conductivereceptacle 25.

Second, the two flexible circuits 314 and 315 can be replaced with apair of flexile wires that are sewn or stitched into a pair of discreteelectrodes, such as described supra with reference to FIGS. 9 through15A-C. FIG. 19 is a contact-surface view of a flexile wire interconnect320 of the wearable monitoring ensemble 300 of FIG. 17. The twoelectrodes 309 and 310 are stitched or sewn 323 and 324 into thecompressible and elastomeric material (not shown) using a pair offlexile wires 321 and 322. The insulation is first stripped from theends of the pair of flexile wires 321 and 322 and an electricalconnection is established between the two electrodes 309 and 310 and thepair of flexile wires 321 and 322. In similar fashion, the pair offlexile wires 321 and 322 can be electrically connected on theiropposite ends to additional components 325 and 326, such as thenon-conductive receptacle 25, electrical terminals, or a wirelesstransceiver, by stripping insulation from and sewing or stitching 327and 328 the other ends of the flexile wires 321 and 322 into theadditional components 325 and 326. Other ways of interconnectingelectrodes and additional components using flexile wire, includingsoldering and crimping, are possible.

Finally, both the two flexible circuits 314 and 315 and the twoelectrodes 309 and 310 can be respectively replaced with a pair offlexile wires and a pair of sewn-in electrodes. FIG. 20 is acontact-surface view of a flexile wire electrode and interconnect 330 ofthe wearable monitoring ensemble 300 of FIG. 17. A pair of electrodes323 and 324 are stitched or sewn into the compressible and elastomericmaterial (not shown) using a pair of flexile wires 321 and 322. The pairof flexile wires 321 and 322 can be electrically connected on theiropposite ends to additional components 325 and 326, such as thenon-conductive receptacle 25, electrical terminals or a wirelesstransceiver, by stripping insulation from and sewing or stitching 327and 328 the other ends of the flexile wires 321 and 322 into theadditional components 325 and 326. Other ways of interconnectingelectrodes and additional components using flexile wire, includingsoldering and crimping, are possible.

The wearable monitoring ensemble 300 is advantageous for both patientsand athletes because the ambulatory apparatus can collect high-qualityECG and physiological data while the wearer engages in activities ofdaily living. ECG data are crucial for diagnosing many cardiovascularconditions, but additional data are often necessary for differentialdiagnoses, such as in diabetic and hypertensive patients. Cardiovascularpatients must take particular care in monitoring their status to avoidrelated adverse events; for example, monitoring temperature can behelpful in cardiovascular patients because cardiovascular systemcompromises patients' capacity for maintaining a normal bodytemperature, and cardiovascular patients may be more susceptible tohypothermia in cool environments.

Athletes also benefit from ECG data combined with additionalphysiological data to prevent adverse cardiac events, including powersports athletes, aged athletes, and young athletes with congenital heartconditions. Moreover, ECG data combined with other physiological datamay aid athletes in optimizing performance. In many instances, bloodsugar measurements may aid in generating a diagnosis, prognosis, andtreatment plan as well as predicting athletic performance. For example,patients with diabetes or blood sugar levels that are greater thannormal are also more likely to develop certain heart diseases, such asischemic heart disease and myocardial infarction. Moreover, multipletypes of physiological data may be combined to predict additionaldisease conditions, such as the combination of high blood pressure,coronary heart disease, and diabetes, which can severely damage cardiacmuscle and lead to heart failure. In addition, blood sugar plays astrong role in athletic performance and recovery; thus, athletes benefitfrom both monitoring their blood sugar before, during, and afterexercise as well as using the monitoring data to elucidate undiagnosedblood sugar conditions. For example, exercise-induced hypoglycemia canseverely hamper performance and may indicate a more serious conditionthat can lead to sudden death.

Monitoring blood pressure may also be key to elucidating a patient's orathlete's underlying physical condition. Hypertension is the greatestrisk factor for cardiovascular disease in both normal and athletepopulations. Dubbed the “silent killer,” hypertension is both common aswell as under-diagnosed and can damage various organs, leading to ahigher risk of left ventricular hypertrophy and sudden death, amongother conditions. Further, combined with ECG data, it may providecritical data for determining a patient's cardiovascular condition. Forexample, as noted above, heart failure is more likely in patients withhigh blood pressure combined with heart disease and blood sugardysregulation. Further, silent ischemia is often diagnosed throughdetecting hypertension and ST depression, which is best observed usingan ambulatory ECG device; a combined prolonged QT interval andhypertension are associated with increased risk of pathologicalcardiovascular conditions, including the risk of sudden death; andhypertensive patients with abnormal T wave patterns exhibit increasedleft ventricular mass, which enhances the risk of adverse cardiacevents, including sudden death. Moreover, while the athletic populationmaintains a lower blood pressure generally, hypertension remains thegreatest cardiac risk factor for athletes. Further, athletes benefitfrom blood pressure monitoring, particularly during exercise, becauseuntreated hypertension can significantly impair athletic performance;moreover, older athletes are at particular risk for undiagnosedhypertension.

Further, detecting abnormal respiratory function may facilitatediagnosis, prognosis, and treatment of certain disorders in bothpatients and athletes. For example, Cheyne-Stokes breathing associatedwith chronic heart failure is a predictor of poor prognoses associatedwith cardiac death. In addition, cardiorespiratory conditions are commonin athletes but are often undiagnosed. Such conditions not only impairperformance, but overtraining with a cardiorespiratory may lead tosevere consequences, such as sudden death due to severebronchoconstriction. Further, sleep decreases the diagnostic efficacy ofECG monitoring alone due to natural heart rate decrease during sleep. Asa patient enters non-rapid eye movement (NREM) sleep, the patientundergoes physiological changes due to less sympathetic nervous systemactivity. Thus, even healthy people may experience sinus bradyarrhythmiaduring sleep, and ECG monitoring alone may reveal whether thebradyarrhythmia is natural or due to a pathological condition, such asan apnea. Further, if a patient experiences other types of arrhythmiasduring sleep, a physician may not be able to determine whether anarrhythmia is due to sleep apnea or other morbidity without measuringthe patient's air flow, which is the flow of air in and out of thepatient's lungs during breathing, or other respiration indicator.However, considering that cardiac manifestations of sleep apnea are mostapparent at night, short-term ECG monitoring during business hours maynot reveal cardiac arrhythmia.

While the invention has been particularly shown and described asreferenced to the embodiments thereof, those skilled in the art willunderstand that the foregoing and other changes in form and detail maybe made therein without departing from the spirit and scope.

What is claimed is:
 1. A wearable electrocardiography monitoringensemble, comprising: a first receptacle defined by two horizontal bandsacross a wearable garment; a second receptacle defined by two furtherhorizontal bands across the wearable garment and positioned under thefirst receptacle; a first electrode assembly positioned within the firstreceptacle and comprising a backing with an electrical connection havingan electrode on one end of the electrical connection and terminating theother end of the electrical connection to connect with a monitorrecorder; a second electrode assembly positioned within the secondreceptacle and comprising a backing with an electrical connection havingan electrode on one end of the electrical connection and terminating theother end of the electrical connection to connect with a further monitorrecorder, wherein the first and second electrodes are alignedlongitudinally in the wearable garment.
 2. A wearableelectrocardiography monitoring ensemble according to claim 1, furthercomprising: a wireless transceiver on the terminated end of theelectrical connection of the first and second electrode assemblies towirelessly connect with the monitor recorder and the further monitorrecorder respectively.
 3. A wearable electrocardiography monitoringensemble according to claim 1, further comprising: one or moreelectrical pads on the terminated end of the electrical connection ofthe first and second electrode assemblies to connect with the monitorrecorder and the further monitor recorder respectively.
 4. A wearableelectrocardiography monitoring ensemble according to claim 3, whereineach of the monitor recorder and the further monitor recorder compriseselectrical pads for mating with the electrical pads of the first andsecond electrode assemblies respectively.
 5. A wearableelectrocardiography monitoring ensemble according to claim 1, whereineach of the electrodes are formed on a flexible circuit.
 6. A wearableelectrocardiography monitoring ensemble according to claim 1, whereineach of the monitor recorder and the further monitor recorder comprise ahousing with electronic circuitry for recording and storing ECG data. 7.A wearable electrocardiography monitoring ensemble according to claim 1,further comprising: a non-conductive receptacle shaped to receive themonitor recorder or the further monitor recorder and positioned on asurface of the backing of one or more of the first and second electrodeassemblies respectively.
 8. A wearable electrocardiography monitoringensemble according to claim 7, wherein the monitor recorder and thefurther monitor recorder are placed in the non-conductive receptacle forthe first and second electrode assemblies respectively.
 9. A wearableelectrocardiography monitoring ensemble according to claim 1, whereinthe wearable garment comprises one or more of a shirt, blouse, andtunic.
 10. A wearable electrocardiography monitoring ensemble accordingto claim 1, wherein the first and second receptacles each providecompressive force imparted by the wearable garment on the first andsecond electrode assemblies respectively.
 11. A method for constructinga wearable electrocardiography monitoring ensemble, comprising:obtaining a wearable garment; defining a receptacle in a wearablegarment via two horizontal bands positioned across the wearable garment,wherein a first electrode assembly is positioned within the firstreceptacle and comprises a backing with an electrical connection havingan electrode on one end of the electrical connection and terminated atthe other end of the electrical connection to connect with a monitorrecorder; and defining a second receptacle by two more horizontal bandspositioned across the wearable garment under the first receptacle,wherein a second electrode assembly is positioned within the secondreceptacle and comprises a backing with an electrical connection havingan electrode on one end of the electrical connection and terminated atthe other end of the electrical connection to connect with a furthermonitor recorder, wherein the first and second electrodes are alignedlongitudinally in the wearable garment.
 12. A method according to claim11, further comprising: positioning a wireless transceiver on theterminated end of the electrical connection of each of the first andsecond electrode assemblies to wirelessly connect with the monitorrecorder and the further monitor recorder respectively.
 13. A methodaccording to claim 11, further comprising: implementing one or moreelectrical pads on the terminated end of the electrical connection ofthe first and second electrode assemblies to connect with the monitorrecorder and the further monitor recorder respectively.
 14. A methodaccording to claim 13, wherein the monitor recorder comprises electricalpads for mating with the electrical pads of the first or secondelectrode assemblies.
 15. A method according to claim 11, wherein eachof the electrodes are formed on a flexible circuit.
 16. A methodaccording to claim 11, wherein the monitor recorder and the furthermonitor recorder each comprise a housing comprising electronic circuitryfor recording and storing ECG data.
 17. A method according to claim 11,further comprising: affixing a non-conductive receptacle shaped toreceive the monitor recorder or the further monitor recorder on thebacking of one or more of the first and second electrode assembliesrespectively.
 18. A method according to claim 17, wherein the monitorrecorder or the further monitor recorder is placed in the non-conductivereceptacle for at least one of the first and second electrode assembliesrespectively.
 19. A method according to claim 11, wherein the wearablegarment comprises one or more of a shirt, blouse, and tunic.
 20. Amethod according to claim 11, wherein the first and second receptacleseach provide compressive force imparted by the wearable garment on thefirst and second electrode assemblies respectively.